I think there's too much stock in the Apple closing off their tracking and somehow advertisers stopped using their ads. That privacy control started in iOS 14.5 in April 2021 and I'm sure it's had some effect but I think it's overblown.

https://www.oberlo.com/statistics/facebook-ad-revenue Up 13% - https://investor.fb.com/investor-news/press-release-details/... Down 1% - https://investor.fb.com/investor-news/press-release-details/... Down 4% - https://investor.fb.com/investor-news/press-release-details/...